Spring loaded terminal seal for sealed refrigeration compressors



Aug. 18, 1959 P. J. HIRTNER 2,900,438

SPRING LOADED TERMINAL SEAL FOR SEALED REFRIGERATION COMPRESSORS Filed Mqrch 7, 1958 IN V EN TOR. 940L- Q/ H/ET/VEZQ,

ATTOE/VEYS.

United States Patent SPRING LOADED TERMINAL SEAL FOR SEALED REFRIGERATION COMPRESSORS Paul J. Hirtner, Tampa, Fla.

Application March 7, 1958, Serial No. 719,795

Claims. (Cl. 174153) This invention relates to a terminal seal for sealed refrigeration units.

During regular use of a unit of the type described above, leaks often are developed in the hermetically sealed refrigeration compressor. It is known that these leaks tend to occur in the area surrounding the electrical terminals.

In the circumstances, it-has represented a considerable problem to make the necessary repair, to halt the leakage. The present invention, accordingly, aims to provide a spring-loaded terminal seal, particularly adapted for use in the repair ofleaking electrical terminals of sealed refrigeration compressors, which terminal seal will be especially adapted to immediately halt the leakage, while still providing the desired good electrical connection between electrical components respectively disposed inside and outside of the sealed refrigeration compressor.

Another object is to provide a spring-loaded terminal seal of the character described that will be adapted for use with a conventional terminal post of a hermetically sealed refrigeration unit, without requiring any modification, disturbance, or replacement of said conventional terminal post.

Another object is to provide, in a device of the character described, a spring-loaded terminal seal which will be applicable with maximum speed and ease by relatively unskilled workers, and without the requirement of special tools.

Another object is to provide a spring-loaded terminal seal of the character described which will be, to all intents and purposes, substantially permanent when properly applied.

Yet another object is to so design the seal that the sealing action not only will not deteriorate over a period of time after'application of the device, but also, will if anything be actually improved in these circumstances.

A further object is to so form the seal that it will compensate for terminal post expansion and contraction.

Yet another object is to provide a seal of the character described that will compensate for heat and age damage on the gasket portion thereof.

A further object'of importance is to so form the terminal seal that it will compensate for gas pressure differences.

Other objects will appear from the following description, the claims appended thereto and from the annexed drawing in which like reference characters designate like parts throughout the several views and wherein:

Figure 1 is a top plan view of the seal according to the present invention, as it appears when properly mounted upon a seal refrigeration compressor only a portion of which is shown, an exteriorly disposed electrical con ductor being omitted;

Figure 2 is a sectional view through the device substantially on line 2-2 of Figure 1, in which the electrical connector has been applied;

Figure 3 is a transverse sectional view substantially on line 3-3 of Figure 2; and

"ice

Figure 4 is a side elevational view of the device.

Referring in detail to the drawing, designated generally at 10 is a spring-loaded terminal seal formed according to the present invention. This includes a shell 12 of inverted cup shape, the external cross sectional configuration of which (see Figure 3) is hexagonal in the illustrated example. However, the cross sectional shape of the shell can vary so far as the external configuration is concerned. It is mainly important, for the purposes of the present invention, that the side wall 13 of the shell has an internal cross section that will cause the same to mate with and grip a nut that is to be described in detail hereinafter, so as to permit conjoint rotation of the nut and shell.

The shell 12, at its upper end, has an upwardly concavoconvex top wall 14 and a flat, circular base 16 is soldered at 18 to the central portion of the top wall, said base providing a support for a lead wire connector.

Integral or otherwise made rigid with the connector base 16 is an upstanding, relatively short stud 20 disposed in coaxial alignment with shell 12. A conventional electrical connector 22 of a lead wire 23 is adapted to be positioned over the stud, and is clamped between the base 16 and a binding nut 24 threaded on the stud.

A base plate 26 of the device is in the form of a flat washer the marginal portion of which is soldered at 28 to the bottom edge of the shell, over the full circumference of the shell (see Figure 4), to provide a fully leaktight connection between the base plate and shell. Interiorly of the shell, base plate 26 has a low, upwardly projecting, circular flange 30.

Underlying the base'plate 26 is a relatively thick sealing gasket 32 of a resiliently compressible, leak-preventing material, such as soft rubber. The center opening '33 of gasket 32 is of a diameter corresponding to the diameter of the center opening of the base plate 26, these openings being registered. As shown in Figure 2, the wall 34 of the refrigeration compressor 35 to which the device is applied has an opening 36 concentric with the registered openings of the gasket and base plate.

Opening 36 is of smaller diameter than the registered openings of the gasket and base plate (see Figure 2) and tightly fitted in opening 36 is a flanged grommet or sleeve 38 of electrical insulation, through which extends an elongated, threaded binding or terminal post 40. Post 40, at its inner end, has a head 42 disposed inside the compressor, and circumposed about the post within the compressor is the electrical connector 43 of an internal lead wire 44, clamped between head 42 and sleeve 38.

Post 40 with its head 42, sleeve 38, and wall 34 having opening 36 are all wholly conventional. Ordinarily, the external lead 23 is connected directly to the post 40, to provide an electrical connection between leads 23 and 44. However, leaks develop where the terminal post 40 extends out of the compressor 36. The present invention thus eliminates said leaks, merely by application of the device 10 over the conventional binding post 40.

The invention further includes a nut 46, mating with and fitting snugly in the hexagonally shaped cavity 47 of shell 12. Nut 46 is free to slide longitudinally of cavity 47, but as will be readily apparent from Figure 3, said nut is required to rotate with the shell 12.

The nut 46 is threaded on the post 40, and interposed between the nut 46 and the flange 30 is a compression, coil spring 48. In use of the device, and assuming that a leak has developed about the binding post 40, as for example between the sleeve 38 and the edge of the opening 36, the external lead 23 is removed from post 40. Then, the entire device 10, which would be previously assembled, is positioned bodily over the post, with gasket 32 being interposed between base plate 26 and wall 34. Nut 46 becomes threadedly engaged with post 40, and on rotation of the shell 12, the nut 46 is rotated and moves downwardly in Figure 2, toward the wall 34. This places the spring 48 under more and more compression, and as a result the pressure of the spring 48 is transmitted to base plate 26 and due to the soldered connection 28, is further transmitted to the shell 12 as well as to the gasket 32. Gasket 32 is thus compressed, and of course the extent of compression of the gasket is determined by the extent to which one chooses to rotate shell 12. It may be noted that gasket 32, while being compressed, does not turn since it binds frictionally against wall 34 while the shell 12 is being rotated for the purpose of compressing the gasket.

After the gasket 32 has been compressed to the desired extent, one need merely apply the connector 22 to the stud 20, after which the nut 24 is threaded onto the stud, for the purpose of providing an electrical connection between leads 23 and 44.

It will be understood that stud 20, its base 16, shell 12 and nut 46 are all of electrically conductive material, and it will be further understood that the nut 46 is in full slidable contact with the inner surface of the wall of the shell so as to produce the necessary electrical connection between leads 23 and 44.

The invention, it has been found, has many desirable characteristics, including an improvement of the sealing action during the passage of time after application of the device. Further, the device can be applied without tools, and in addition compensates for expansion and contraction of the terminal post, heat and age damage on the gasket, and gas pressure differences. Still further, the device does not require any modifications or redesign of the conventional parts, and permits repair of the compressor directly on the site 'without the heavy expense that has heretofore been required.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

1. A terminal seal for a refrigeration unit having an externally projecting terminal post constituting a connection between external and internal lead wires of said unit, comprising: an electrically conductive shell proportioned to enclose said post, said shell including an end wall at one end thereof; electrically conductive means on said end wall for connecting said external lead wire to the shell, the shell having a cavity the wall of which is of non-circular cross section; an electrically conductive nut within the cavity slidably engaged with the wall of said cavity and having a cross-section mating with that of said wall, for conjoint rotation of the nut and shell and for sliding of the nut along the wall of the cavity, said nut being threadedly engageable with the post; a base plate sealably connected to the other end of the shell; a compression, coil spring interposed between said base plate and nut; and a gasket adapted to extend about said post in contact with the base plate, thus to be interposed between the base plate and said unit, said gasket being of a compressible material for compression of the same responsive to threading the nut on said post in a direction toward the base plate.

2. A terminal seal for a refrigeration unit having an externally projecting terminal post constituting a connection between external and internal lead wires of said unit, comprising: an electrically conductive shell proportioned to enclose said post, said shell including an end wall at one end thereof; electrically conductive means on said end wall for connecting said external lead wire to the shell, the shell having a cavity the Wall of which is of non-circular cross section; an electrically conductive nut within the cavity slidably engaged with the wall of said cavity and having a cross section mating with that of said wall, for conjoint rotation of the nut and shell and for sliding of the nut along the wall of the cavity, said nut being threadedly engageable with the post; a base plate sealably connected to the other end of the shell; a compression coil spring interposed between said base plate and nut; and a gasket adapted to extend about said post in contact with the base plate, thus to be interposed between the base plate and said unit, said gasket being of a compressible material for compression of the same responsive to threading of the nut on said post in a direction toward the base plate, said base plate projecting interiorly of the shell and having, inside the shell, a flange providing a seat for said spring.

3. A terminal seal for a refrigeration unit having an externally projecting terminal post constituting a connection between external and internal lead wires of said unit, comprising: a shell free to rotate about and proportioned to enclose said post, at least a part of the shell being electrically conductive; abutment means on the shell; electrically conductive means on said part for mounting said external lead wire on the shell; an electrically conductive nut within the shell engaged with said part of the shell for rotation conjointly with the shell and for movement axially thereof, said nut being threadedly engageable with said post; resilient, yielding means interposed between the abutment means and nut and tensioned to bias the shell axially in one direction, toward the unit, when the nut is threaded along the post in the same direction; and gasket means adapted to extend about said post and disposed between the shell and said unit for compression therebetween when the shell is shifted in said direction.

4. A terminal seal for a refrigeration unit having an externally projecting terminal post constituting a connection between external and internal lead wires of said unit, comprising: a shell free to rotate about and proportioned to enclose said post, at least a part of said shell being electrically conductive; electrically conductive means engaged with said part and adapted for connection to said external lead wire; an electrically conductive nut within the shell engaged with said part of the shell for rotation conjointly with the shell and for movement axially thereof, said nut being threadedly engageable with said post, the shell being of cup-shape with one end formed open; abutment means engaged with the shell and extending inwardly of the shell; resilient, yielding means interposed between the nut and abutment means and tensioned to bias the shell axially in one direction, toward the unit, on threading of the nut along the post in the same direction; and annular gasket means concentric with the shell and adapted to extend about said post in a position in which said gasket means is interposed between said end of the shell and said unit, for compression therebetween when the shell moves in said direction.

5. A terminal seal for a refrigeration unit having an externally projecting terminal post constituting a connection between external and internal lead wires of said unit, comprising: a shell at least a part of which is electrically conductive, said shell being free to rotate about and being proportioned to enclose said post; electrically conductive means engaged with said part adapted for mounting said external lead wire on the shell; an electrically conductive nut within the shell engaged with said part for rotation conjointly with the shell and for movement axially thereof, said nut being threadedly engageable with said post; an annular base plate sealably connected to the shell; a compression spring interposed between the nut and base plate, for biasing the shell and base plate axially in one direction, toward the unit, responsive to threading of the nut along the post in the same direction; and gasket means adapted to extend about said post and disposed in engagement with the base plate, thus to compress the gasket means between the base plate and said unit responsive to movement of the base plate in said direction.

Roux Aug. 7, 1917 Link Aug. 5, 1958 

